Essentially, this is pretty close to the effect of a friendly amendment except that the friendly amendment requires the acquiescence of the person who seconded the motion and possibly those who have already voted yes.

In terms of TB specific rules and procedures, a friendly amendment would permit those who have already voted to change their votes (normally not permitted for TB votes) and also, according to the current discussion, not change the timing of the vote.

Withdrawal of the motion would appear to be a unilateral action by the person who made the initial motion. The clock would then reset when the replacement motion is moved and seconded. Site-wide announcement would be required followed by the new feedback period before voting can begin.

At the moment, I don't have strong feelings about these two options (except to point ouut that I've already said that if those who have voted yes are allowed to veto the friendly amendment, then we need to specify that the privilege only applies to those who voted before the friendly amendment was mentioned, in order to prevent someone from quickly voting yes on a deficient motion just to be able to torpedo it by refusing to approve the friendly amendment), but if changes are left to the discretion of the TB president (for example, to determine unilaterally what changes are to be treated as minor), then the scope of such changes must be defined so as to be clearly limited.